AFAIK there is no hidden code of bolt data contained in the part number - there's no way to determine what it is without actually finding it in a long, long list.
Note; the "Group" numbers identify the purpose (function) of the part in question, not the part itself. There is no individual data or dimensions. A single group number covers every part ever made for that purpose, regardless of size, thread, age, etc. Group 0.269 includes every 216, 235 & 261 cylinder head 1937-63, even though they are not always interchangeable.
